| Business | Phone |
| Prairie Resource Group 413 Wisconsin Ave B, Oak Park 60302 | (708) 763-9100 |
| Himmelfarb Group 1119 Pleasant St, Oak Park 60302 | (708) 848-0086 |
| Infosec Institute 1515 N Harlem Ave, Oak Park 60302 | (708) 848-0059 |
| Reed Organization Ltd 801 South Blvd, Oak Park 60302 | (708) 386-8653 |
| Training Solutions Work 130 Le Moyne Pkwy, Oak Park 60302 | (708) 386-0696 |